Colloidal Liquid Crystals Confined to Synthetic Tactoids

Area of Science:

• Soft Matter Physics
• Liquid Crystals
• Colloidal Science

Background:

• Liquid crystals confined to small volumes exhibit complex behavior due to boundary conditions.
• Filamentous viruses (fd-viruses) serve as model colloidal particles for studying liquid crystalline phases.
• Tactoids are nematic droplets formed during phase separation, offering insights into confined liquid crystal behavior.

Purpose of the Study:

• To investigate the orientational patterns of filamentous fd-viruses in quasi-2D lens-shaped chambers.
• To explore how varying chamber geometry influences liquid crystal director fields.
• To identify novel configurations beyond those predicted for 3D tactoids.

Main Methods:

• Utilizing quasi-2D lens-shaped chambers with controlled size and aspect ratios.
• Observing liquid crystal director fields using fluorescence microscopy.
• Employing Monte Carlo simulations to analyze observed configurations and their stability.

Main Results:

• Discovered novel director field configurations in confined fd-virus systems.
• Identified a phase diagram with unique patterns not previously predicted for 3D tactoids.
• Demonstrated that these novel states are metastable yet exhibit long-lived behavior.

Conclusions:

• The geometry of confinement significantly dictates liquid crystal orientational patterns.
• Multiple dynamic relaxation pathways contribute to the multiplicity of observed metastable states.
• This study expands the understanding of liquid crystalline behavior in confined geometries, particularly with biological colloids.